Aleppo: At dawn Syrian civil servants Abu Asaad and Abu Abdo each begin their commutes across the war-torn city of Aleppo, a once-short journey that now takes 10 hours.

A frontline slices through the former economic hub from north to south, with rebels in control of more than half of the devastated city.

People like 45-year-old Abu Asaad, who works as a driver for the state, must travel for more than 400 kilometres (250 miles) by bus just to get from one side to the other.

They face grave danger as they detour through an area under the control of the Islamic State (IS) jihadist group, which has seized large areas in Syria and neighbouring Iraq.

Until a year ago, residents could cross from one side of Aleppo to the other through a checkpoint at Bustan al-Qasr. But because of snipers, it was closed.

After working for 10 days straight in a regime-held neighbourhood, Abu Asaad waits for the bus at a station in the New Aleppo district to go home to Shaar, a rebel area just five kilometres (three miles) away.

To get there the bus must first cross an area that is under army control, before reaching a desert zone that has become a no-man`s land over the course of the more than three-year-old war.

He and other passengers then risk their lives as their bus drives through Al-Bab, an area of Aleppo province that is controlled by IS. From there, the bus travels back into Aleppo city.

"Before we reach the IS checkpoint, women climb into the back of the bus and veil their faces completely," said bus driver Mohammad, who makes the risky journey three times a month.

"They are not allowed to travel alone, according to the laws imposed by the jihadists. So we must make sure they are accompanied by their husband or brother. I check carefully, because I will pay the price if anything goes wrong," he told AFP.

For Abu Asaad, each journey is now a dive into the unknown.

"A jihadist from Daesh gets on the bus, armed with a sword rather than a Kalashnikov," he said, using an Arabic acronym for IS.

"He checks everyone`s documents, and forces suspects to get off the bus, threatening them with his weapon. I always say I am a tailor, because if I admit I am a civil servant, they will throw me in jail," Abu Asaad said.

But all of the forces on the ground -- loyalists, the IS and the rebels -- have their databases.

"One mistake, and you disappear," he said.Abu Abdo lives in the rebel district of Sakhur. He too crosses the frontline to get to the ministry where he works.

"Our journey from one side of Aleppo to the other is filled with danger. It used to take 10 minutes, but now it takes 10 hours because of a big detour," he told AFP.

"There are many checkpoints and dangers along the way, but I must make the journey because I am a civil servant and I have no other source of income. Sometimes, I make the journey twice or three times a week. God have mercy on us," he said.

The bus ticket price has shot up because of the war.

It used to cost just 20 Syrian pounds to get from one neighbourhood to the other. Now it costs 2,500 pounds ($12.5) from the government to the rebel sides.

About 800 people make the journey each day from the regime side, while roughly the same number leave from the rebel area, said Munir, who runs the bus station.

People living on both sides say loyalists and rebels demand bribes to let them through their checkpoints, but IS poses the biggest danger for drivers.

One told AFP he received 30 lashes because the jihadists thought his beard was too short.

Another said he was lashed because he forgot to switch off the radio before he reached the IS checkpoint.

A third driver said he spent 48 hours in an IS jail, and that he was only set free when he could recite a prayer correctly.

Many passengers make sure to have one last cigarette before climbing on board, because IS forbids smoking.

"This is the road of fear. It is absurd to have to drive for hours through the desert to get from one side of the city to the other," said Abu Ahmad, who travelled to the regime-held side of Aleppo to see his doctor.